Liquid fuel burner



April 5, 1932. L A, COCKUN 1,852,290

LIQUID FUEL BURNER Filed OCT.. 3. 1929 L.A. COCKLIN1^ NVENTOR www ATTO R N EY Patented Apr. 5, 1932 LEWIS A. COGKLIN, OF GRISWOLD, IOWA LIQUID FUEL BURNER Application :tiled October 3, 1929. Serial No. 397,019.

My invention relates to oil or liquid fuel burners of the type wherein the liquid fuel is delivered to a porous filler or wick contained within an open-topped retort, the combustion of the fuel occurring at the top of said retort, and the heat from the zone of combustion serving to vaporize the liquid fuel in the upperlportions of the filler or wick. It is the object of my invention to provide in a burner of this type means for limiting or inhibiting the transmission of heat from the zone of combustion of the fuel to the lower portion of the retort, whereby to maintain a zone of vaporization in the upper portions only of the filler or wick, and to enable the maintenance of a high temperature in the uppermost portions of the wick material, whereby to prevent or limit clogging of the wick by accumulationof solid carbonaceous residues from the vaporized fuel, and tofacilitate the my invention, and Fig. 2 is a bottom view of the annular baille or extension-ring. n

The burner illustrated in the drawings is of the general type whereinthere is provided an annular retort having an outer wall 5 and an inner wall 6, the latter providing a tubular portion or air-flue through which is supplied most of the air required for combustion of the fuel. In the structure shown, the retort rests upon the upturned end portion of a horizontal tube or conduit 7 of which the opening in said upturned end portion is in register with the air-flue.

As installed for use, air is supplied to the conduit 7 by a suitable blower, or in some in stances natural instead of forced draft may be employed, the usual arrangement for burners of this type being such that substantially all of the air supplied to the combustionchamber of the furnace in which the burner is used enters said chamber through said conduit 7 At the upper end of the air-flue there is provided a removable cap or spreader 8 which is held in spaced relation to the upper end of the line by means of shouldered lugs 9, the lower surface 10 of said spreader being torically curved and adapted to direct air from the flue outwardly and .slightly downward so as to impinge upon the upper surface of the wick or filler 11, with which the retort is lled to a level near the upper end of the air-flue. The wick or filler 11 comprises granular fragments of refractory mineral composition, of porous or spongy consistency, and having relatively low-heat conductivity. A flat ring 12 is supported' on fixed lugs 13 near the bottom of the retort, to provide an annular space or distributing channel 14 from which the iiller material is excluded, and to which the liquid fuel is supplied through a suitable pipe 15. The ring 12 lits loosely within the retort, so that the fuel from the distributing channel may low about the edges thereof, and rise into the filler 11 to a level determined by the fuel-control devices associated with the burner. The outer wall of the retort, at a level slightly below the upper end of the air-flue, is shouldered outh wardly to form a ledge, from which the marginal flange 16 extends up to a level above the top of the air-flue. Seated upon the shoulder or ledge within the flange 16 is the extension-ring 17, which has a plurality of lugs 18 fitting within the flange to center the ring therewith. Said lugs 18 are extended slightly below thelower edge of the ring 17 whereby to support the same slightly above the ledge, and to` thus provide a' small airspace between the ring and the wall of the retort. The inner side of the extension-ring at the lower part thereof is substantially in register with the inner side of the retort-wall, the upper portion of the ring is flared outwardly, and at the upper end of the ring an integral flange 19 extends out to the same diameter as that of the wall-flange 16.

In the operation of the burner, the gravitationa-l level of the liquid fuel in the retort varies according to the rate at which the fuel is supplied thereto, and some of the liquid is carried above the gravitational level, or to the upper portion of the wick material, by the capillary action of said material, due to the porosity thereof above mentioned'. After operation of the burner has been started by igniting the fuel at the top of theA retort, the i,

upper portions of the wick material quickly become heated to a temperature such as to cause vaporization of the liquid as it approaches the upper surface, and the resulting l5 gas or vapor rising from the wick becomes mixed with the air emerging from beneath the spreader 8. The impinging air-current, sweeping across the upper .surface of the ller or wick material, carries the flame radially outward, and at the outer edge of the retort the liame is directed upwardly' by the extension-ring` 17. Said ring thus-serves asl a deflector or baille to limit lateral spreading of the flame, and will become intensely heated. l5 The heat radiated inwardly from the ring tends to raise the temperature 'of the upper portions of the filler or wick material 11, to more effectively vaporize the oil in said upper portions, but by reason of the low conductivity of said material the-heat from the upper portions is not transmitted to the lower portions of the material in sufficient amount to cause vaporiz'ation of the oil below the desired vaporiz'ing Zone. Some of the heat from the ring 17 is transmitted tothe outer wall of the retort, but the heating of said Wall is limited by reason of the spaced relation of the ring thereto, the air-space between the parts serving as an insulator, and actua-l conduction of heat from the ring to the wall occurring only through the limited areas 'of eonta'ct afforded by the lugs 18. In burners of large size the eXtension-ringmaybe formed of non-metallic refractory material, but in small burners it is found that the extension'- ringmay'be of castmetalwithout causing the conduction 'of heat therefrom to the retortwa'll to become objectio-nably great.

It is desirable that 'the insulating airspace between the extension-ring and the wall of the retort be close to or substantially at the level 'of the upper surface ofthe wick or filler 11, so Ithat the wall of the retort will not be directly exposed to the Haine at said surface. It is also desirable Vthat should the flame of the burner become 'extinguished while the liquid fuel is being supplied to the retort, or should lthe fuel supply be turned on without igniting the burner, or if an eX- cessive quantity offuel 'be supplied to the retort at any time," so that the liquid level in "the retort would rise to the top thereof, the eXce-ssofliquid may flow over the upper end of the iiuejo, passing down through said flue to the conduit 7"rather than to overflow `the outer wallof the retort. These desirable results are attained by the extension of vthe outer flange 16 to a level above the upper end of the flue 6, so that while said flue extends above' the surface ofthe fillerf11, and the latter extends to the level ofthenshoulder or ledge on ,which the yextension-'ring rests, 4no 'overflow can occur Yexcept at the inner wall orair-flu'e. Y

Now, having described my invention, what I claim and desire to secure by Letters Patent is:

1. In a liquid fuel burner, a retort having an annular chamber open at ythe top, the inner wall of saidv annular chamber forming a vertical air-passage, spreading meansat the upper endof saidv airpassage fordirccting the air therefrom outwardly across the top of the annular chamber, a filler of porous granular refractory material of low heat conductivity filling said annular chamber, means for supplying liquid fuel to the lower portion of the annular chamber, and means insulated from theouter wall of the retort and eXtending labovethe lill-er material peripherallyof the annular Ychamber to bale laterallyk and direct upwardly the'flame from the surface 0f the filler. Y

2. In a liquid fuel burner,the combination with an open-topped retort having Va vcentral afir-passage, porous refractory `materialillLV ing said retort, means forlsupplying:liquid fuel to the Alower portion of the retort, and' means 'for directing -aiir from the central pas'- sage outwardly across .the surface yof the filling material, of an annular baille-member arf ranged peripherally of the retortabovethe surface of the fil/ling material, and means foi` limiting conduction of heat from` said balile-member `to the Wall Aof the retort.

Y3. In an oil burner, the combination with an annular retort 'having a central airdlne and al shouldered outer Wall forming la Iledge at a level slightly belowthe u per 'end -o'f the air-flue, porous granular re ractory ma# teria-l filling said retort substantiallyto the level of "said -ledlge,a 'spreader disposed 'over the 'upper end of said aireflue'andadapted to direct the airA therefrom outwardly across the surface of the fl'ling material, and means for 4supplyingfoil 'to vthe rlower portion ofsaid retort, of a ring `disposed above said ledge and forminglan upwardfextension'of the reftort wall, sadri'nglbeing 'spaced from l'sind wall 'to limit lconduction -or heat fromthe ring 'to the 'wal-1. Y n v e. In a 'liquid ruellburnenthecombination with afreto'rt'having annular chamber open atfthe ftop,=the inner wall of 4said-Lannular chamber forming lan 'airiiue'a'nd lt'heol'lte'r wall of said annular chamber being 'shouldered outwardly to forma Vledgea'ta level below. the top of said air-flue, a liller'of porous granular material lling said annular chamber to substantially the level "of said ledge, means for 'supplying liquid fuel to the lower portion of said1 annular chamber, and means for directing air'from the top of said air-flue outwardly -acrossgthensurface of 'said filler, of amarginal"flangefformed in. Vtegrally with said .outer wall io'f the retort and extending upwardly yfrom said 'ledge Vto a level above the `top of the -aireflueyund'a of the retort.

LEWIS A. COCKLIN. 

